/*
 * Copyright (C) 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef WTF_HashSet_h
#define WTF_HashSet_h

#include "FastAllocBase.h"
#include "HashTable.h"

namespace WTF {

	template<typename Value, typename HashFunctions, typename Traits> class HashSet;
	template<typename Value, typename HashFunctions, typename Traits>
	void deleteAllValues(const HashSet<Value, HashFunctions, Traits>&);
	template<typename Value, typename HashFunctions, typename Traits>
	void fastDeleteAllValues(const HashSet<Value, HashFunctions, Traits>&);

	template<typename T> struct IdentityExtractor;

	template<typename ValueArg, typename HashArg = typename DefaultHash<ValueArg>::Hash,
		typename TraitsArg = HashTraits<ValueArg> > class HashSet {
			WTF_MAKE_FAST_ALLOCATED;
		private:
			typedef HashArg HashFunctions;
			typedef TraitsArg ValueTraits;

		public:
			typedef typename ValueTraits::TraitType ValueType;

		private:
			typedef HashTable<ValueType, ValueType, IdentityExtractor<ValueType>,
				HashFunctions, ValueTraits, ValueTraits> HashTableType;

		public:
			typedef HashTableIteratorAdapter<HashTableType, ValueType> iterator;
			typedef HashTableConstIteratorAdapter<HashTableType, ValueType> const_iterator;

			void swap(HashSet&);

			int size() const;
			int capacity() const;
			bool isEmpty() const;

			iterator begin();
			iterator end();
			const_iterator begin() const;
			const_iterator end() const;

			iterator find(const ValueType&);
			const_iterator find(const ValueType&) const;
			bool contains(const ValueType&) const;

			// An alternate version of find() that finds the object by hashing and comparing
			// with some other type, to avoid the cost of type conversion. HashTranslator
			// must have the following function members:
			//   static unsigned hash(const T&);
			//   static bool equal(const ValueType&, const T&);
			template<typename T, typename HashTranslator> iterator find(const T&);
			template<typename T, typename HashTranslator> const_iterator find(const T&) const;
			template<typename T, typename HashTranslator> bool contains(const T&) const;

			// The return value is a pair of an interator to the new value's location, 
			// and a bool that is true if an new entry was added.
			pair<iterator, bool> add(const ValueType&);

			// An alternate version of add() that finds the object by hashing and comparing
			// with some other type, to avoid the cost of type conversion if the object is already
			// in the table. HashTranslator must have the following function members:
			//   static unsigned hash(const T&);
			//   static bool equal(const ValueType&, const T&);
			//   static translate(ValueType&, const T&, unsigned hashCode);
			template<typename T, typename HashTranslator> pair<iterator, bool> add(const T&);

			void remove(const ValueType&);
			void remove(iterator);
			void clear();

		private:
			friend void deleteAllValues<>(const HashSet&);
			friend void fastDeleteAllValues<>(const HashSet&);

			HashTableType m_impl;
		};

	template<typename T> struct IdentityExtractor {
		static const T& extract(const T& t) { return t; }
	};

	template<typename ValueType, typename ValueTraits, typename T, typename Translator>
	struct HashSetTranslatorAdapter {
		static unsigned hash(const T& key) { return Translator::hash(key); }
		static bool equal(const ValueType& a, const T& b) { return Translator::equal(a, b); }
		static void translate(ValueType& location, const T& key, const T&, unsigned hashCode)
		{
			Translator::translate(location, key, hashCode);
		}
	};

	template<typename T, typename U, typename V>
	inline void HashSet<T, U, V>::swap(HashSet& other)
	{
		m_impl.swap(other.m_impl);
	}

	template<typename T, typename U, typename V>
	inline int HashSet<T, U, V>::size() const
	{
		return m_impl.size();
	}

	template<typename T, typename U, typename V>
	inline int HashSet<T, U, V>::capacity() const
	{
		return m_impl.capacity();
	}

	template<typename T, typename U, typename V>
	inline bool HashSet<T, U, V>::isEmpty() const
	{
		return m_impl.isEmpty();
	}

	template<typename T, typename U, typename V>
	inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::begin()
	{
		return m_impl.begin();
	}

	template<typename T, typename U, typename V>
	inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::end()
	{
		return m_impl.end();
	}

	template<typename T, typename U, typename V>
	inline typename HashSet<T, U, V>::const_iterator HashSet<T, U, V>::begin() const
	{
		return m_impl.begin();
	}
	template<typename T, typename U, typename V>
	inline typename HashSet<T, U, V>::const_iterator HashSet<T, U, V>::end() const
	{
		return m_impl.end();
	}
	template<typename T, typename U, typename V>
	inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::find(const ValueType& value)
	{
		return m_impl.find(value);
	}
	template<typename T, typename U, typename V>
	inline typename HashSet<T, U, V>::const_iterator HashSet<T, U, V>::find(const ValueType& value) const
	{
		return m_impl.find(value);
	}

	template<typename T, typename U, typename V>
	inline bool HashSet<T, U, V>::contains(const ValueType& value) const
	{
		return m_impl.contains(value);
	}

	template<typename Value, typename HashFunctions, typename Traits>
	template<typename T, typename HashTranslator>
	typename HashSet<Value, HashFunctions, Traits>::iterator
		inline HashSet<Value, HashFunctions, Traits>::find(const T& value)
	{
			typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, HashTranslator> Adapter;
			return m_impl.template find<T, Adapter>(value);
		}
	template<typename Value, typename HashFunctions, typename Traits>
	template<typename T, typename HashTranslator>
	typename HashSet<Value, HashFunctions, Traits>::const_iterator
		inline HashSet<Value, HashFunctions, Traits>::find(const T& value) const
	{
			typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, HashTranslator> Adapter;
			return m_impl.template find<T, Adapter>(value);
		}

	template<typename Value, typename HashFunctions, typename Traits>
	template<typename T, typename HashTranslator>
	inline bool HashSet<Value, HashFunctions, Traits>::contains(const T& value) const
	{
		typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, HashTranslator> Adapter;
		return m_impl.template contains<T, Adapter>(value);
	}

	template<typename T, typename U, typename V>
	pair<typename HashSet<T, U, V>::iterator, bool> HashSet<T, U, V>::add(const ValueType& value)
	{
		return m_impl.add(value);
	}

	template<typename Value, typename HashFunctions, typename Traits>
	template<typename T, typename HashTranslator>
	inline pair<typename HashSet<Value, HashFunctions, Traits>::iterator, bool>
		HashSet<Value, HashFunctions, Traits>::add(const T& value)
	{
			typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, HashTranslator> Adapter;
			return m_impl.template addPassingHashCode<T, T, Adapter>(value, value);
		}

	template<typename T, typename U, typename V>
	inline void HashSet<T, U, V>::remove(iterator it)
	{
		if (it.m_impl == m_impl.end())
			return;
		m_impl.internalCheckTableConsistency();
		m_impl.removeWithoutEntryConsistencyCheck(it.m_impl);
	}

	template<typename T, typename U, typename V>
	inline void HashSet<T, U, V>::remove(const ValueType& value)
	{
		remove(find(value));
	}

	template<typename T, typename U, typename V>
	inline void HashSet<T, U, V>::clear()
	{
		m_impl.clear();
	}

	template<typename ValueType, typename HashTableType>
	void deleteAllValues(HashTableType& collection)
	{
		typedef typename HashTableType::const_iterator iterator;
		iterator end = collection.end();
		for (iterator it = collection.begin(); it != end; ++it)
			delete *it;
	}

	template<typename T, typename U, typename V>
	inline void deleteAllValues(const HashSet<T, U, V>& collection)
	{
		deleteAllValues<typename HashSet<T, U, V>::ValueType>(collection.m_impl);
	}

	template<typename ValueType, typename HashTableType>
	void fastDeleteAllValues(HashTableType& collection)
	{
		typedef typename HashTableType::const_iterator iterator;
		iterator end = collection.end();
		for (iterator it = collection.begin(); it != end; ++it)
			fastDelete(*it);
	}

	template<typename T, typename U, typename V>
	inline void fastDeleteAllValues(const HashSet<T, U, V>& collection)
	{
		fastDeleteAllValues<typename HashSet<T, U, V>::ValueType>(collection.m_impl);
	}

	template<typename T, typename U, typename V, typename W>
	inline void copyToVector(const HashSet<T, U, V>& collection, W& vector)
	{
		typedef typename HashSet<T, U, V>::const_iterator iterator;

		vector.resize(collection.size());

		iterator it = collection.begin();
		iterator end = collection.end();
		for (unsigned i = 0; it != end; ++it, ++i)
			vector[i] = *it;
	}

} // namespace WTF

using WTF::HashSet;

#endif /* WTF_HashSet_h */
